Organic Chemistry-I

(i) Select the most stable carbonium ion from the following.

1. C⁺H₃
2. (CH₃)₂C⁺H
3. CH₃−C⁺H₂
4. (CH₃)₃C⁺

(ii) Resonance by Hybrid is represented as -

1. → ←
2. ⇇
3. →
4. =

(iii) No bond resonance is

1. Inductive effect
2. Mesomeric effect
3. Steric effect
4. Hyperconjugation effect

(iv) Resolution is a process in which a racemic mixture is separated into -

1. (+) isomers only
2. (−) isomers only

(v) Resolution is a process in which a racemic mixture is separated into -

1. (+) and (−) isomers
2. None of these

(vi) Process in which an asymmetric compound is synthesised from a symmetric to yield (+) and (−) isomers directly

1. Symmetric synthesis
2. Asymmetric synthesis
3. Racemisation
4. None of the above

(vii) Optically active compound with absence of chiral carbon atom.

1. Allenes
2. Benzaldehyde
3. Toluene
4. None of the above

(viii) Free Radical with highest stability is.

1. −Cl
2. C₆H₅−O•
3. C₆H₅•
4. CH₃•

(ix) Most stable carbocation of the following is.

1. (CH₃)₂C⁺H
2. CH₃−CH₂C⁺H₂
3. C₆H₅CH₂⁺
4. (CH₃)₃C⁺

(x) Transition stage is a

1. True molecule
2. Not a true molecule
3. Sometimes true and sometimes not true
4. None of the above

(xi) Photochemical Reaction starts with.

1. Homolysis
2. Nucleophilic
3. SN Mechanism
4. E₁ Mechanism

(xii) Isotopic labelling means.

1. An atom replaced by an isotope
2. An Atom Replaced by Halogen
3. Atom replaced by metal
4. None of these

(xiii) The SN² reactions are of

1. Zero order
2. First order
3. Second order
4. None of them

(xiv) The tertiary alkyl Halides undergo hydrolysis of.

1. SN₁ Mechanism
2. SN₂ Mechanism

(xv) Which one of the following is used as phase transfer catalyst.

1. Primary Amine
2. Tertiary Amine
3. Tertiary Nitroalkane
4. Quaternary Ammonium salt

2. Explain Huckel's Rule.

OR

Show your acquaintance with inclusion compound.

3. What are elements of symmetry.

OR

Write a note on chirability

4. How does conformation effects reactivity.

OR

Write a note on Taft Equation.

5. Write short notes on the following (Any one)

1. Types of Reactions
2. Hammond's postulates

6. Write a brief note on Regioselectivity.

OR

Phase transfer catalysis.

7. Write a detailed note on resonance.

OR

Explain crown Ether complex with suitable examples.

8. Give optical Activity of Allenes in detail.

OR

Give methods of resolutions in detail.

9. What are carbocations ? Give structure and chemical properties.

OR

Write short note on the following :-

1. Substituent constant

5. Write short notes on the following (Any one)

1. Free Radical

10. Give different methods of determination of mechanism (Any two)

11. Write detailed note on any two of the following :-

1. SET Mechanism
2. Classical carbocations
3. SN₁ Mechanism